Hollow metal joist



oct. 16, 192s. 1,688,016

B. J. KLASEN HoLLow METAL JoIs'1` Filed June` 23, 1927 aunado@ 7 mjlamezzllfhaselz Patented Oct. 16, 1928.

UfN-ETED SlT I'ES BENJAMIN KLAASEN,` or) HIGHLAND-PARK; MICHIGAN:

HOLLOW` METAL JOIST.

Application( l'edJ une 123,

rllhev present invention pertains to ahollow metal joist .for replacing solid metal orwood. en j oists,.beams and simi-lar structures` in building 'construction. Y

The Vjirrincipad .object ,of the invention isv to provide a device of this character which may. readilyv 'be assembled from simple metallic parts.. rllhe nature-ofthe-fparts' is such that they may be formed by simple and inexpensive mechanical operations. These parts are provided with simple interlocking elements so that no auxiliary att-aching or joining devices are necessarily required in the assembly and completion of the joist.

rllhe device of the invention consists essentially of a pair of flanged lateral members and intermediate connecting members which join the flanges of opposed side members. rlhe formation of the connecting members is preferably such that they are capable of sup porting wooden nailing strips at the upper and lower faces of the hollow structure. The connecting members are constructed to hold the flanges of opposed members slightly spaced from one another, so that narrow spaces are retained longitudinally of the hollow structure to provide access to the wooden strips for the purpose of nailing other structural elements thereto. 'K

rlhe invention is fully disclosed by way of example in the following descriptionr andfin the accompanying drawingsa in which- Figure 1 is a perspective view, partly broken away7 of a` hollow metal joist constructed according to the invention;

F ig. 2 is a transverse section thereof; f

Fig. 3 is a perspective view of one of the intermediate trusses; and

Fig. 4 is a perspective view of one of the end pieces.

Reference to these views will now be made by use of like characters which are employed to designate correspondingparts throughout.

The sides of the j oist consist each of a metal plate 1 having a flange 2 at each longitudinal edge. The flanges are again turned under as at 3 to provide a channel formation 4. The connecting members between opposed side members consist each of a channel 5 having substantially the same longitudinal extent as the members 1. Each chanel member has outwardly extending flanges 6 from the walls thereof, and these flanges are bent back upon,b themselves as at 7 and projected somewhat into the channel space to theextent of the depth of the channel formations 4. It will 1927: seriaiNoz, zomerse.-v

beI seen .in FigureQthatthe flanges 6 lproject* laterallyrfar enough to engage the .inner faces.; of the sidek members, 1, andA from the. descrip.- i tion of the portions 7 ust given, it is apparent y that these. portions fit. snugly beneath the flanges 2. Thewidth of the; connecting menA ber ispreferably such thatalorgitudinal space:4 8,. is retained between the` connected flanges ofopposed side members 1 at the top and bottom of the hollow structure thus formed. Y

f In order that other structural units may be nailed to the'hollow joist,V a woodenvbar or nailing strip 9 is passed into each channel 5 and is preferably coextensive withthe unit; The members 9 are accessible through the slots 8 retained between the flanges 2 of opposed side members.

Openings 10 may be formed in the side members 1 for the passage of piping, wiring and the like through the hollow joist. The joist is reinforced at intervals by trusses 11 fitted therein and preferably disposed at the ends of the openings. .Each truss consists of a metal sheet 12 which is stamped to form flanges 13 at the longer edges thereof. The body'y of the sheet 12 is stamped out to form at each end an opening 14, the material taken out of this opening being ysplit and bentover in the form of a pair of flanges 15 parallel to the members 13 and thereby yforming channel formations at the corners. The openings 14 have thesame cross sectional area as the interiorof the channels 5 in order to receive the longitudinal nailing Astrips 9. The outer flangesl?) carry each a central tongue 16 which preferably lies in the lsame plane as the flange when the truss is inserted. The truss is moved into the joist until the tongue is fully exposed at an end of one of the openings 10, and the tongue is then bent back upon vitself to engage the outer surface of the adjacent side member 1 as illustrated in Figure 1.

After the trusses 11 have been inserted, the ends of the joist are fitted with closure members of the type shown in Figure 4. These members consist of a blank of metal stamped 'Y to form a pair of parallel channel sections 17 joined by a back 18. The back is kcut awayy at the ends to form openings 19 for the purpose of accommodating the strips 9 in the manner described in kconnection with Figure Y `3. The outer walls of the channels 17 have their free edges bent back upon themselvesto form narrow channels 20 adapted to receive the ends of the plates l. The closure inembers extend for a. considerable distance into the hollow truss and thereby reinforce the same at the ends where it is most likely to be supported and where greater strength is needed.

Although specific embodiments of the invention have been illustrated and described, it will be understood that Various alterations in the details of construction may be made without departing from the scope of the invention as indicated by the appended claims.

What I claim is A l. A hollow metal joist comprising flanged side members and a channel connecting member inserted between said side member-s ant joining the flanges of opposed side members,

said flanges extending over the open side of said Channel member, said connecting member holding said flanges in spaced relation7 and a nailing piece inserted in said channel connecting member and accessible through the space between the flanges. l i

2. A hollow metal joist comprising flanged side members and a connecting member inserted between said side members and joining the flanges of opposed side members, strengthening end members lit-ted into the ends of the hollow structure thus formed, and lnailing pieces passing through said end members and connecting` members and disposed adjacen said anges. v

In testimony whereof I aliix my signature.

BENJAMIN J. KLAASEN. 

